In order to perform efficient management of a number of devices that are connected to a network; methods are known in which the devices are managed in groups. Such methods of managing devices in groups include a static group management method, in which a predetermined group structure is used, and a dynamic group management method, in which groups are generated and deleted depending on the situation.    Non-patent Literature 1: M. Baugher et al., “RFC 3547, The Group Domain of Interpretation”, [online], July 2003, retrieved from the Internet: <URL: http://www.ietf.org/rfc/rfc3547.txt>
In the dynamic group management method, although flexible management can be performed depending on the situation, ensuring scalability remains an issue.